Well, one must question the practicality behind the lightsaber as a weapon. First off, a lightsaber weighs approx. 45 lbs. How can they be twirling those things with one hand if they weigh that much? The answer: the force, duh. Only a Jedi can wield a lightsaber, and that's because they are force-sensitive beings. If anyone else used one, they'd be more likely to hurt themself than their enemy.

Also, we know that the force experiences disturbances that can be felt flowing through the entire galaxy. If a Jedi NEEDS to use the Force in order to use a lightsaber, then the occassional chaotic discrepancy might hinder a Jedi or Sith while using the Force, hence those superfluous-looking series of theatrical blade-twirls you're seeing in this YTMND. A lightsaber is guided by the force, and the force doesn't always operate in ways that seem rational. The choreographer was probably joking, though.